docs: def _bsp_traverse(
      node_iter: Iterable[tcod.bsp.BSP],
      callback: Callable[[tcod.bsp.BSP, Any], None],
      userData: Any,
  ) -> None:
      """pack callback into a handle for use with the callback
      _pycall_bsp_callback
      """
      for node in node_iter:
          callback(node, userData)